Technical Field
The present invention relates to a vehicle seat.
Related Art
In a vehicle seat described in Japanese Patent Application Laid-Open (JP-A) No. 2009-107571, a pad member (seatback pad) of a seatback is supported from the seat rear side by a planar spring structure. The planar spring structure is formed in a lattice shape from wire, and is coupled to a seatback frame by connecting wires. The planar spring structure resiliently supports the seatback pad from the seat rear side, enabling the comfort (ride comfort) of a seated occupant to be secured during normal operation.
In the event of a rear-end shunt (a rear-end collision), load from the seated occupant moving toward the seat rear side under inertia is input to the planar spring structure, thereby releasing a coupled state between the planar spring structure and the connecting wires, or between the connecting wires and the seatback frame. The back and waist of the seated occupant accordingly enter into the seatback, and the head of the seated occupant is swiftly supported by a headrest. This thereby enables a reduction in whiplash injury, thereby contributing to improved occupant protection performance.
Recently, seatback frames are sometimes formed entirely from resin, for example in the interests of reducing the weight of a vehicle seat. There are demands to improve rear-end collision occupant protection performance, while securing the comfort of a seated occupant during normal operation, in vehicle seats provided with such resin seatback frames.